A commonly used painkiller might be too risky for people to keep taking, suggests a new study published this week in the BMJ. It found that people who use diclofenac, a non-steroidal anti-inflammatory drug (NSAID), are more likely to come down with cardiovascular disease than people who take other NSAIDs or acetaminophen.

Diclofenac is sold under various brand names, including Voltaren, Cambia, and Solaraze, both over-the-counter and via prescription. While the drug is perhaps not as well-known as other NSAIDs in the U.S., such as ibuprofen, it’s actually one of the most popular and routinely recommended drugs sold across the world, in both developing and developed nations. Diclofenac is categorizedas an essential medicine in more than 70 countries, according to a 2013 study.

For years, however, doctors have been worried about diclofenac’s potential heart risks. Some research has suggested the drug could raise the risk of cardiovascular complications, similar to the now-withdrawn NSAID rofecoxib, otherwise known as Vioxx, which was pulled from the market in 2004, five years after it was widely approved. Because it would likely be unethical (and costly) to conduct the sort of large-scale randomized trial that could definitively confirm these suspicions, though, the Danish researchers behind the new paper opted for an unique sort of study.

Using national population and prescription drug registries, they were able to look at the medical records of over 6 million Danish adults from 1996 to 2016. Then they used this data to emulate hundreds of clinical trials at once. For example, they looked at people who reported taking diclofenac in 1996, then tracked their health for the next 12 months, while comparing them to people who either took other NSAIDs, acetaminophen, or nothing at all……..more here